Led lamp

ABSTRACT

An LED lamp A includes a plurality of LED modules  2  each including an LED chip  21 , and a support member  1  including a support surface  1   a  on which the LED modules  2  are mounted. The LED modules  2  include a plurality of kinds of LED modules, or a first through a third LED modules  2 A,  2 B and  2 C different from each other in directivity characteristics that represent light intensity distribution with respect to light emission directions. This arrangement ensures that the entire surrounding area can be illuminated with sufficient brightness.

TECHNICAL FIELD

The present invention relates to an LED lamp that uses a light emittingdiode (hereinafter referred to as “LED”) as the light source.

BACKGROUND ART

FIG. 63 shows an example of conventional LED lamp (see Patent Document1, for example). The LED lamp X shown in the figure includes aplate-like substrate 91, a plurality of LED modules 92 mounted on thesubstrate 91, a heat dissipation member 95 attached to the substrate 91,a case 93 accommodating the substrate 91, and terminals 94. Thesubstrate 91 is provided with a wiring pattern, not shown, connected tothe LED modules 92 and the terminal 94. The LED lamp X is structuredsuch that the LED modules 92 can be turned on when the terminals 94 arefitted into inlet ports of a socket of a general-use fluorescentlighting fixture.

The general-use fluorescent lighting fixture herein refers to lightingfixtures widely used for interior lighting as the main application, andmore specifically, lighting fixtures which use, for example in Japan, acommercial power supply (e.g. AC 100 v) and to which a JIS C7617straight-tube fluorescent lamp or a JIS C7618 circular fluorescent lampcan be attached. (Hereinafter, such a general-use fluorescent lightingfixture is simply referred to as a “lighting fixture”.)

When the LED lamp X is attached to a lighting fixture on e.g. an indoorceiling, the main light emission direction of the LED modules 92 isoriented downward. When the LED modules 92 are turned on, most part ofthe light emitted from the LED modules 92 is directed in the main lightemission direction of the LED modules 92. Thus, sufficient brightnesscannot be obtained at the surrounding area of the LED lamp X, especiallynear the sides of the LED lamp X.

As compared with this, general-use fluorescent lamps can emit light fromalmost the entire surface of the case, so that the surrounding area ofthe lighting fixture is uniformly illuminated to obtain sufficientbrightness. Thus, as compared with general-use fluorescent lamps, theLED lamp X has a disadvantage that sufficient brightness cannot beobtained especially near the sides of the lamp.

-   Patent Document 1: JP-U-H06-54103

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The present invention has been proposed under the circumstancesdescribed above. It is therefore an object of the present invention toprovide an LED lamp that can illuminate the surrounding area withsufficient brightness.

Means for Solving the Problem

According to the present invention, there is provided an LED lampcomprising a plurality of LED modules each including an LED chip and asupport member including a support surface on which the LED modules aremounted. The LED modules comprise a plurality of kinds of LED modulesdifferent from each other in directivity characteristics that representlight intensity distribution with respect to a light emission direction.

In a preferred embodiment of the present invention, the plurality of LEDmodules include a first LED module arranged adjacent to the center ofthe support surface. The directivity characteristics of the first LEDmodule are such that light intensity in the normal direction of thesupport surface is relatively high, as compared with other LED modules.

In a preferred embodiment of the present invention, the first LED moduleincludes a reflector that surrounds the LED chip and that is open in thenormal direction.

In a preferred embodiment of the present invention, the first LED modulefurther includes a sealing resin that seals the LED chip. The sealingresin is filled in a space surrounded by the reflector.

In a preferred embodiment of the present invention, the dimension of thefirst LED module in the normal direction of the support surface of thesupport member is smaller than a dimension of the first LED module inthe in-plane direction of the support surface.

In a preferred embodiment of the present invention, the first LED moduleincludes a substrate on which the LED chip is mounted, and the substrateis provided with a mount terminal on a surface thereof opposite from asurface on which the LED chip is mounted.

In a preferred embodiment of the present invention, the plurality of LEDmodules include a second LED module arranged adjacent to an edge of thesupport surface. The directivity characteristics of the second LEDmodule are such that light intensity in an outward direction within theplane of the support surface is relatively high, as compared with otherLED modules.

In a preferred embodiment of the present invention, the second LEDmodule includes a reflector that surrounds the LED chip and that is openin the outward direction within the plane of the support surface.

In a preferred embodiment of the present invention, the second LEDmodule further includes a sealing resin that seals the LED chip. thesealing resin is filled in a space surrounded by the reflector.

In a preferred embodiment of the present invention, the second LEDmodule includes a substrate on which the LED chip is mounted. The secondLED module is mounted on the support member, with a side surface of thesubstrate facing the support surface of the support member.

In a preferred embodiment of the present invention, a dimension of thesecond LED module in an in-plane direction of the support member islarger than the dimension of the second LED module in the normaldirection of the support member.

In a preferred embodiment of the present invention, the plurality of LEDmodules further include a third LED module arranged between the firstLED module and the second LED module. The directivity characteristics ofthe third LED module are such that the light intensity distribution withrespect to the light emission direction is relatively uniform, ascompared with the first and the second LED modules.

In a preferred embodiment of the present invention, the third LED moduleincludes a substrate on which the LED chip is mounted, and the substrateis provided with a mount terminal on a surface thereof opposite from thesurface on which the LED chip is mounted.

In a preferred embodiment of the present invention, the third LED moduleincludes a sealing resin that seals the LED chip. The sealing resin isexposed in both of the normal direction of the support surface and thein-plane direction of the support surface.

In a preferred embodiment of the present invention, the support surfacehas an elongated shape. A plurality of first LED modules are arranged inthe longitudinal direction of the support surface adjacent to the centerof the support surface. A plurality of second LED modules are arrangedalong edges of the support surface that are spaced from each other inthe width direction. A plurality of third LED modules are arranged inthe longitudinal direction at each of the regions between the first LEDmodules and the second LED modules.

In a preferred embodiment of the present invention, the LED lamp furthercomprises a case that accommodates the first through the third LEDmodules and the support member and allows light emitted from the firstthrough the third LED modules to pass through while diffusing the light.

In a preferred embodiment of the present invention, the case iscylindrical.

In a preferred embodiment of the present invention, the support membercomprises an insulating substrate, and the LED lamp further comprises aheat dissipation member attached to the insulating substrate at aportion opposite from the support surface.

In a preferred embodiment of the present invention, the case is formedwith a projecting piece that projects inward and supports the substrate.

In a preferred embodiment of the present invention, the projecting pieceis in engagement with the heat dissipation member.

Other features and advantages of the present invention will become moreapparent from the detailed description given below with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an example of LED lamp according tothe present invention;

FIG. 2 is a schematic sectional view taken along liens II-II in FIG. 1;

FIG. 3 is a top view of a first LED module;

FIG. 4 is a schematic sectional view taken along lines IV-IV in FIG. 3;

FIG. 5 is a bottom view of the first LED module;

FIG. 6 shows directivity characteristics of the first LED module;

FIG. 7 is a side view of a second LED module;

FIG. 8 is a schematic sectional view taken along lines VIII-VIII in FIG.7;

FIG. 9 shows the second LED module mounted on a support substrate;

FIG. 10 shows directivity characteristics of the second LED module;

FIG. 11 is a side view showing a variation of the second LED module;

FIG. 12 is a schematic sectional view taken along lines XII-XII in FIG.11;

FIG. 13 shows directivity characteristics of a variation of the secondLED module;

FIG. 14 is a top view of a third LED module;

FIG. 15 is a schematic sectional view taken along lines XV-XV in FIG.14;

FIG. 16 is a bottom view of the third LED module;

FIG. 17 shows directivity characteristics of the third LED module;

FIG. 18 is a view for explaining advantages of the LED lamp;

FIG. 19 shows a variation of the LED lamp;

FIG. 20 is a schematic view showing the outer configuration of avariation of the first LED module;

FIG. 21 shows directivity characteristics of the first LED module shownin FIG. 20;

FIG. 22 is a schematic view showing the outer configuration of avariation of the first LED module;

FIG. 23 shows directivity characteristics of the first LED module shownin FIG. 22;

FIG. 24 is a schematic view showing the outer configuration of avariation of the first LED module;

FIG. 25 shows directivity characteristics of the first LED module shownin FIG. 24, designed to emit red light and green light;

FIG. 26 shows directivity characteristics of the first LED module shownin FIG. 24, designed to emit blue light and red light;

FIG. 27 is a schematic view showing the outer configuration of avariation of the first LED module;

FIG. 28 shows directivity characteristics of the first LED module shownin FIG. 27;

FIG. 29 is a schematic view showing the outer configuration of avariation of the first LED module;

FIG. 30 shows directivity characteristics of the first LED module shownin FIG. 29;

FIG. 31 is a schematic view showing the outer configuration of avariation of the first LED module;

FIG. 32 shows directivity characteristics of the first LED module shownin FIG. 31;

FIG. 33 is a schematic view showing the outer configuration of avariation of the second LED module;

FIG. 34 shows directivity characteristics of the second LED module shownin FIG. 33;

FIG. 35 is a schematic view showing the outer configuration of avariation of the second LED module;

FIG. 36 shows directivity characteristics of the second LED module shownin FIG. 35;

FIG. 37 is a schematic view showing the outer configuration of avariation of the second LED module;

FIG. 38 shows directivity characteristics of the second LED module shownin FIG. 37;

FIG. 39 is a schematic view showing the outer configuration of avariation of the second LED module;

FIG. 40 shows directivity characteristics of the second LED module shownin FIG. 39;

FIG. 41 is a schematic view showing the outer configuration of avariation of the second LED module;

FIG. 42 shows directivity characteristics of the second LED module shownin FIG. 41;

FIG. 43 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 44 shows directivity characteristics of the third LED module shownin FIG. 43;

FIG. 45 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 46 shows directivity characteristics of the third LED module shownin FIG. 45;

FIG. 47 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 48 shows directivity characteristics of the third LED module shownin FIG. 47;

FIG. 49 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 50 shows directivity characteristics of the third LED module shownin FIG. 49;

FIG. 51 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 52 shows directivity characteristics of the third LED module shownin FIG. 51;

FIG. 53 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 54 shows directivity characteristics of the third LED module shownin FIG. 53;

FIG. 55 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 56 shows directivity characteristics of the third LED module shownin FIG. 55;

FIG. 57 is a schematic view showing the outer configuration of avariation of the third LED module;

FIG. 58 shows directivity characteristics of the third LED module shownin FIG. 57;

FIG. 59 is a side view showing a variation of the LED module;

FIG. 60 shows directivity characteristics of the LED module shown inFIG. 59;

FIG. 61 is a side view showing a variation of the LED module;

FIG. 62 shows directivity characteristics of the LED module shown inFIG. 61; and

FIG. 63 is a sectional view showing an example of a conventional LEDlamp.

MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention are described below withreference to the accompanying drawings.

FIGS. 1 and 2 show an example of LED lamp according to the presentinvention. FIG. 1 is a schematic perspective view of the LED lamp,whereas FIG. 2 is a schematic sectional view taken along lines II-II inFIG. 1.

The LED lamp A of this embodiment includes a support substrate 1, aplurality of LED modules 2, a heat dissipation member 3, a case 4 and apair of bases 5. The LED lamp A is to be used as attached to ageneral-use fluorescent lighting fixture, as a substitute for e.g. astraight-tube fluorescent lamp. When the general-use fluorescentlighting fixture is attached to e.g. an indoor ceiling, the LED lamp Ais usually mounted to the lighting fixture in such a manner that themain light emission direction of the LED modules 2 is oriented downward.

The support substrate 1 supports the LED modules 2. The supportsubstrate 1 is made of e.g. glass-fiber-reinforced epoxy resin and hasan elongated plate-like shape. The mount surface 1 a of the supportsubstrate 1 is formed with a wiring pattern, not shown, made of e.g. Cufor supplying power to the LED modules 2.

As shown in FIG. 1, the LED modules 2 are mounted in a matrixarrangement on the mount surface 1 a. The arrangement and number of theLED modules 2 on the mount surface 1 a of the support substrate 1 shownin FIG. 1 are merely an example, and the present invention is notlimited to this example. In this embodiment, the LED modules 2 comprisefirst, second and third LED modules 2A, 2B and 2C. The first, the secondand the third LED modules 2A, 2B and 2C differ from each other inluminous intensity distribution (directivity characteristics).

FIGS. 3-5 show the first LED module 2A. The first LED module 2A includesan LED chip 21, a substrate 22, metal wiring patterns 23 and 24 spacedfrom each other, a wire 25, a frame 26 and a sealing resin 27. The firstLED module 2A is about 1.6 mm in length, about 0.8 mm in width and about0.55 mm in thickness. Thus, the thickness, which is the dimension in thedirection normal to the mount surface 1 a, is smaller than the lengthand the width, which are dimensions in the in-plane direction of themount surface 1 a.

The directivity characteristics of the LED modules 2A are such that theintensity of the light emitted from the LED chip 21 is relatively highin the direction normal to the mount surface 1 a of the supportsubstrate 1. FIG. 6 shows the directivity characteristics of the firstLED module 2A. In this directivity characteristics, the relativeintensity RI is highest at the direction angle Da of 0°. In thisembodiment, as shown in FIGS. 1 and 2, the first LED modules 2A arearranged in the longitudinal direction of the support substrate 1 at thecenter of the support substrate 1. Each of the first LED modules 2A isarranged in such a manner that its main light emission directioncorresponds to the direction normal to the mount surface 1 a.

As shown in FIG. 4, the LED chip 21 is mounted on the mount surface 22 aof the substrate 22 via the wiring patterns 23 and 24. The LED chip 21comprises lamination of e.g. an n-type semiconductor, a p-typesemiconductor and an active layer sandwiched between thesesemiconductors (none of these are shown). The LED chip 21 emits bluelight when it is made of e.g. a GaN-based semiconductor.

The LED chip 21 includes two electrodes (not shown) on the upper and thelower surfaces. By mounting the LED chip 21 on the obverse surface ofthe lead 23, the electrode on the lower surface of the LED chip 21 iselectrically connected to the wiring pattern 23. As shown in FIGS. 4 and5, the wiring pattern 23 reaches the reverse surface 22 b of thesubstrate 22 through the inner surface of a recess 28 having asemicircular cross section. The wiring pattern 23 on the reverse surface22 b constitutes a mount terminal 29 to be bonded to the wiring pattern,not shown, of the support substrate 1. The electrode on the uppersurface of the LED chip 21 is connected to the wiring pattern 23, 24 viathe wire 25. Thus, the electrode on the upper surface of the LED chip 21is electrically connected to the wiring pattern 23, 24. Similarly to thewiring pattern 23, the wiring pattern 23, 24 reaches the reverse surface22 b of the substrate 22 through a recess 28. The lead 24 on the reversesurface 22 b constitutes a mount terminal 29 to be bonded to the wiringpattern of the support substrate 1.

The frame 26 is made of e.g. a white resin and extends upward from theperiphery of the mount surface 22 a. The frame 26 includes a reflectivesurface 26 a surrounding the LED chip 21, the wire 25 and the sealingresin 27. The reflective surface 26 a reflects the light emitted fromthe LED chip 21 to cause the light to travel upward. In this way, thefirst LED module 2A is designed as an LED module with a reflector. Withthis arrangement, in the first LED module 2A, the intensity of the lightfrom the LED chip 21 which travels in the direction normal to the mountsurface 1 a of the support substrate 1 is increased.

The sealing resin 27 is provided for protecting the LED chip 21 and thewire 25. The sealing resin 27 comprises e.g. a silicone resin thattransmits light emitted from the LED chip 21. In the case where afluorescent material that emits yellow light when excited by blue lightis mixed in the sealing resin 27, white light can be emitted from theLED module 2. Instead of the fluorescent material that emits yellowlight, fluorescent materials each of which emits green light or redlight may be mixed in.

FIGS. 7 and 8 show the second LED module 2B. In FIGS. 7 and 8, theelements that are identical or similar to those of the first LED module2A are designated by the same reference signs as those used for thefirst LED module. The second LED module 2B is about 3.8 mm in length,about 1 mm in width and about 0.6 mm in thickness. Thus, the thickness,which is the dimension in the direction normal to the mount surface 1 a,is smaller than the length and the width, which are dimensions in thein-plane direction of the mount surface 1 a.

As shown in FIG. 7, in the second LED module 2B, the leads 23, 24 extendfrom the mount surface 22 a of the substrate 22 onto the side surface 22c. The portion of each of the leads 23 and 24 which covers the sidesurface 22 c constitutes a mount terminal 29. As shown in FIG. 9, thesecond LED module 2B is disposed on the support substrate 1 in such amanner that the substrate 22 is oriented sideways, and fixed to thesupport substrate 1 by bonding the mount terminals 29 to the wiringpattern (not shown) of the support substrate 1 using solder 30. Thus,unlike the first LED module 2A, the main light emission direction of theLED chip 21 of the second LED module 2B corresponds to the in-planedirection of the mount surface 1 a of the support substrate 1.

FIG. 10 shows the directivity characteristics of the second LED module2B. In this figure, the direction corresponding to the direction angleDa of 0° is the outward direction within the plane of the mount surface1 a of the support substrate 1. In the second LED module 2B, therelative intensity RI is highest at the direction angle Da of 0°, i.e.,in the outward direction within the plane of the mount surface 1 a. Inthis embodiment, as shown in FIGS. 1 and 2, the second LED modules 2Bare arranged along the edges of the support substrate 1 that are spacedin the width direction.

As the second LED module, the second LED module 2B′ as shown in FIGS. 11and 12 may be employed which is not provided with a frame 26 and hencedoes not have a reflector. In the second LED module 2B′, the sealingresin 27 is substantially trapezoidal in side view. The leads 23, 24 ofthe second LED module 2B′ extend from the mount surface 22 a of thesubstrate 22 onto the reverse surface 22 b via the side surface 22 c. Inthe second LED module 2B′ again, the portion of each of the leads 23 and24 which is positioned on the side surface 22 c constitutes a mountterminal 29. FIG. 13 shows the directivity characteristics of the secondLED module 2B′. As compared with the second LED module 2B, the relativeintensity RI is high in a wider region in the outward direction withinthe plane of the mount surface 1 a.

FIGS. 14-16 show the third LED module 2C. In these figures, the elementsthat are identical or similar to those of the first and the second LEDmodules 2A, 2B are designated by the same reference signs as those usedfor the first and the second LED modules. The third LED module 2C isabout 1.6 mm in length, about 0.8 mm in width and about 0.36 mm inthickness. Thus, the thickness, which is the dimension in the directionnormal to the mount surface 1 a, is smaller than the length and thewidth, which are dimensions in the in-plane direction of the mountsurface 1 a.

The third LED module 2C is different from the first and the second LEDmodules 2A, 2B in that the third LED module does not have a frame 26 onthe substrate 22. That is, as shown in FIG. 15, in the third LED module2C, the sealing resin 27 is substantially trapezoidal in side view andits most part is exposed. Thus, in the third LED module 2C, light fromthe LED chip 21 is emitted not only in the main light emission directionbut also obliquely or sideways at a relatively high ratio.

FIG. 17 shows the directivity characteristics of the third LED module2C. In a strict sense, in this directivity characteristics, the relativeintensity RI is not highest at the direction angle Da of 0°. As comparedwith the first LED module 2A, for example, the relative intensity RI atthe direction angle Da of 0° is slightly lower, but the distribution ofthe relative intensity RI is more uniform. In this embodiment, as shownin FIGS. 1 and 2, the LED modules 2C are aligned on the mount surface 1a in each of the regions between the first LED modules 2A and the secondLED modules 2B. Each of the third LED modules 2C is arranged such thatthe main light emission direction of the LED chip 21 corresponds to thedirection perpendicular to the mount surface 1 a of the supportsubstrate 1.

The heat dissipation member 3 is provided for dissipating the heatgenerated at the LED modules 2 and attached to the reverse side of thesupport substrate 1, as shown in FIGS. 1 and 2. The heat dissipationmember 3 is made of e.g. Al and has a thin block-like shape extending inthe longitudinal direction of the support substrate 1.

The surface of the heat dissipation member 3 may be treated to provideinsulation so that the heat dissipation member can directly support theLED modules 2. That is, the support substrate 1 may be dispensed with.In this case, a wiring pattern similar to the wiring pattern formed onthe mount surface 1 a of the support substrate 1 is formed between theLED modules 2 and e.g. an insulating sheet (not shown) having insulatingproperty. With this arrangement, it is not necessary to prepare thesupport substrate 1 for mounting the LED modules 2, in addition to theheat dissipation member 3, so that the cost for the parts is reduced.

The case 4 is provided for accommodating the support substrate 1, theheat dissipation member 3 and so on, and is cylindrical, as shown inFIG. 2. The case 4 comprises a single-piece member made by extrusion ofa synthetic resin such as polycarbonate. When part of the light emittedfrom the LED modules 2 reaches the inner surface of the case 4, the case4 allows the light to pass through while diffusing the light.

A pair of projecting pieces 41 are formed integrally on the innersurface of the case 4 to project inward. In the state shown in FIG. 2,part of the heat dissipation member 3 is held in engagement with theprojecting pieces 41 so that the movement of the heat dissipation member3 relative to the case 4 in a direction perpendicular to the center axisO1 (upward direction in the figure) is restricted. The support substrate1, the heat dissipation member 3 and so on are housed in the case 4 byinserting the heat dissipation member 3 into the case 4 by slidingmovement on the inner side of the projecting pieces 41.

The paired bases 5 are to be attached to a socket (not shown) of ageneral-use fluorescent lighting fixture to supply AC power from acommercial power supply. As shown in FIG. 1, each of the bases 5 isprovided with two terminals 51. The terminals 51 are the portions to befitted into the insertion ports of the socket of the general-usefluorescent lighting fixture.

The advantages of the LED lamp A are described below with reference toFIG. 18. FIG. 18 shows the cross section of the LED lamp A attached to ageneral-use fluorescent lighting fixture fixed to e.g. an indoor ceilingP. It is to be noted that the illustration of FIG. 18 is upside down.

According to this embodiment, when the LED lamp A is turned on, light isemitted from the LED chips 21 of the first through the third LED modules2A, 2B and 2C. The dotted line SA shows the directivity characteristicsof the first LED modules 2A.

The directivity characteristics of the first LED modules 2A are suchthat the intensity of light is extremely high in the direction normal tothe mount surface 1 a. The dotted lines SB show the directivitycharacteristics of the second LED modules 2B. The directivitycharacteristics of the second LED modules 2B are such that the intensityof light is high in the outward direction within the plane of the mountsurface 1 a. The dotted lines SC show the directivity characteristics ofthe third LED modules 2C. The directivity characteristics of the thirdLED modules 2C are such that the intensity of light is relativelyuniform around a line normal to the mount surface 1 a.

In this way, since the first through the third LED modules 2A, 2B and 2Cthat are different from each other in light directivity characteristicsare disposed on the support substrate 1 in the present embodiment, thelight emitted from the LED lamp A is directed substantially uniformly inalmost all directions except the direction toward the ceiling P. Thus,sufficient brightness is obtained at every point around the LED lamp A.

The LED lamp according to the present invention is not limited to theforegoing embodiment. The specific structure of each part of the LEDlamp according to the present invention may be changed in design in manyways. For instance, the shapes of the support substrate 1, the LEDmodules 2, the heat dissipation member 3 and the case 4 and so on arenot limited to those described above. The manner of mounting the LEDmodules 2 on the support substrate 1 (e.g. the way of alignment, numberand arrangement of the LED modules 2) is not limited to the foregoingembodiment.

In the foregoing embodiment, the movement of the heat dissipation member3 is restricted by the paired projecting pieces 41 projecting from theinner side of the case 4 (see FIG. 2). Instead of this arrangement, apair of projecting pieces 41′ as shown in FIG. 19 may be employed torestrict the movement of the heat dissipation member 3 and the supportsubstrate 1.

In the foregoing embodiment, the arrangement of the LED modules isadapted to an LED lamp used as a substitute for a straight-tubefluorescent lamp. However, the present invention is not limited to this,and the arrangement of the LED modules may be adapted to an LED lampused as a substitute for a circular fluorescent lamp or a downlight usedas embedded in an indoor ceiling.

As the first through the third LED modules 2A, 2B and 2C, the LEDmodules shown in FIGS. 20-58 may be employed. These figures show theschematic outer configuration or directivity characteristics of each LEDmodule. Each view showing the outer configuration of an LED moduleincludes, from the top, a top view, a side view and a bottom view, and aright side view on the right of the top view. FIGS. 20-32 each shows anLED module with a reflector which can be employed as the first LEDmodule 2A. The directivity characteristics of the first LED module 2Aare such that the relative intensity RI is highest at the directionangle Da of 0°. FIGS. 33-42 each shows an LED module for sideways lightemission which can be employed as the second LED module 2B. Thedirectivity characteristics of the second LED module 2B are such thatthe direction in which the direction angle Da=0° corresponds to theoutward direction within the plane of the mount surface 1 a of thesupport substrate 1. FIGS. 43-58 each shows an LED module with uniformintensity distribution which can be employed as the third LED module 2C.The directivity characteristics of the third LED module 2C are such thatthe relative intensity RI is not highest at the direction angle Da of0°. It is to be noted that the LED modules shown in FIGS. 24 and 49 areof the type that emits two colors of light, whereas the LED modulesshown in FIGS. 29, 39 and 57 are of the type that emits three colors oflight.

Instead of the above-described LED modules, bullet-shaped LED modules asshown in FIGS. 59 through 62 may be employed. The bullet-shaped LEDmodule shown in FIG. 59 can be mounted on the support substrate 1vertically or horizontally. Thus, by appropriately selecting themounting orientation, the direction in which the relative intensity RIis highest can be set to correspond to the direction normal to the mountsurface of the support substrate 1 or to the outward direction withinthe plane of the mount surface. The bullet-shaped LED module shown inFIG. 61 has a simpler structure as compared with the bullet-shaped LEDmodule shown in FIG. 59, and the directivity characteristics of thisbullet-shaped LED module is such that the intensity of light is high inthe direction normal to the mount surface of the support substrate 1.Instead of bullet-shaped LED modules shown in FIGS. 59 through 62, usemay be made of a conventional LED module having two lead pins. In usingsuch a conventional LED module, the LED module is mounted by guidingeach lead pin through the support substrate 1 or bending each lead pin.This allows the LED module to have directivity characteristics such thatthe intensity of light is relatively high in the direction normal to themount surface of the support substrate 1 or the outward direction withinthe plane of the mount surface of the support substrate 1.

1-20. (canceled)
 21. An LED lamp that is configured to be fitted to afluorescent lighting fixture having inlet ports, the LED lampcomprising: a substrate including first and second ends spaced from eachother in a longitudinal direction of the substrate; a plurality of LEDsmounted on a mount surface of the substrate; a light-transmitting covercovering the plurality of LEDs; and a pair of bases attached to thefirst and second ends of the substrate, respectively, wherein each ofthe plurality of LEDs comprises: a first lead; a second lead spacedapart from the first lead in a first direction; a LED chip electricallyconnected to the first lead and the second lead; a case covering thefirst lead and the second lead in a manner such that the first lead andthe second lead include bottom surfaces, respectively, that are flushwith each other and are exposed from the case, the case surrounding theLED chip when viewed in a second direction perpendicular to a surface ofthe first lead; and a transparent sealing resin filled in a spacedefined by the case such that the LED chip is covered by the sealingresin, wherein each of the bases includes a pair of terminals eachconfigured to be fitted into one of the inlet ports of the fluorescentlighting fixture.
 22. The LED lamp according to claim 21, wherein eachof the LEDs has a thickness which is a dimension in a direction normalto the mount surface, a length which is a dimension along the firstdirection, and a width which is a dimension along a second directionperpendicular to the direction normal to the mount surface and the firstdirection, the thickness being smaller than the length and the width.23. The LED lamp according to claim 21, wherein the plurality of LEDscomprise a first group of LEDs arranged in a row along the longitudinaldirection of the substrate and at a center of the substrate as viewed inthe longitudinal direction.
 24. The LED lamp according to claim 23,wherein each of the first group of LEDs comprises a reflector configuredto reflect light emitted from the LED chip of said each of the firstgroup of LEDs.
 25. The LED lamp according to claim 21, wherein the firstlead and the second lead of said each of the plurality of LEDs arebonded to a wiring pattern formed on the substrate.
 26. The LED lampaccording to claim 21, wherein said each of the plurality of LEDscomprises a chip-substrate supporting the LED chip, and the casecomprises a frame that is made of a white resin and extends upward froma periphery of the chip-substrate.
 27. The LED lamp according to claim26, wherein in said each of the plurality of LEDs, the frame comprises areflective surface surrounding the LED chip and the sealing resin. 28.The LED lamp according to claim 21, wherein in said each of theplurality of LEDs, the sealing resin comprises: a silicone resin thattransmits light from the LED chip; and a fluorescent material that emitsyellow light when excited by blue light.
 29. The LED lamp according toclaim 21, wherein the cover is semicircular or circular in crosssection.
 30. The LED lamp according to claim 21, wherein in said each ofthe plurality of LEDs, each of the first lead and the second leadprotrudes outward from the case in plan view.
 31. An LED lamp that isconfigured to be fitted to a fluorescent lighting fixture having inletports, the LED lamp comprising: a substrate including first and secondends spaced from each other in a longitudinal direction of thesubstrate; a plurality of LEDs mounted on a mount surface of thesubstrate; a light-transmitting cover covering the plurality of LEDs;and a pair of bases attached to the first and second ends of thesubstrate, respectively, wherein each of the plurality of LEDscomprises: a LED chip; and a reflector surrounding the LED chip asviewed in a first direction perpendicular to the mount surface of thesubstrate such that light emitted from the LED chip has highestreflective intensity in the first direction, wherein each of the basesincludes a pair of terminals each configured to be fitted into one ofthe inlet ports of the fluorescent lighting fixture.
 32. The LED lampaccording to claim 31, wherein each of the LEDs has a thickness which isa dimension in the first direction, a length which is a dimension alonga second direction perpendicular to the first direction, and a widthwhich is a dimension along a third direction perpendicular to the firstdirection and the second direction, the thickness being smaller than thelength and the width.
 33. The LED lamp according to claim 31, whereinthe plurality of LEDs comprise a first group of LEDs arranged in a rowalong the longitudinal direction of the substrate and at a center of thesubstrate as viewed in the longitudinal direction.
 34. The LED lampaccording to claim 31, wherein the first lead and the second lead ofsaid each of the plurality of LEDs are bonded to a wiring pattern formedon the substrate.
 35. The LED lamp according to claim 31, wherein saideach of the plurality of LEDs comprises a chip-substrate supporting theLED chip, and the reflector is made of a white resin and extends upwardfrom a periphery of the chip-substrate.
 36. The LED lamp according toclaim 31, wherein each of the plurality of LEDs comprises a transparentsealing resin covering the LED chip, and the reflector surrounds thesealing resin as viewed in the first direction.
 37. The LED lampaccording to claim 36, wherein in said each of the plurality of LEDs,the sealing resin comprises: a silicone resin that transmits light fromthe LED chip; and a fluorescent material that emits yellow light whenexcited by blue light.
 38. The LED lamp according to claim 31, whereinthe cover is semicircular or circular in cross section.
 39. The LED lampaccording to claim 31, wherein said each of the plurality of LEDscomprises a first lead and a second lead spaced apart from the firstlead in the second direction, each of the first lead and the second leadbeing electrically connected to the LED chip.
 40. The LED lamp accordingto claim 39, wherein each of the plurality of LEDs further comprises acase covering a part of the first lead and a part of the second lead,each of the first lead and the second lead protruding outward from thecase in plan view.